Which Countries Have the Strongest and Weakest Submarine Fleets?

TL;DR

The strongest submarine fleets combine stealth, endurance, modern weapons, and operational readiness rather than relying on fleet size alone. Among 471 known military submarines across 43 countries, China has 58 and Russia has 62, but Russia has a larger nuclear-powered share. Smaller diesel fleets remain valuable for coastal defense, while nuclear submarines support long-range power projection and deterrence. Read on to see why raw rankings can be misleading.

Transcript

• This is every military submarine on earth, at least the ones we know about. I've separated them out by each country. "Whoever rules the waves rules the world," is a saying that rings especially true in recent years as global power dynamics are shifting before our eyes. Submarines represent ocean power. So today, let's look at the 471 known milita... Read More

Key Insights

• At least 471 known military submarines are divided among 43 countries, though experts disagree about exact totals. Most submarine-operating countries maintain fleets of fewer than a dozen vessels, reflecting the high strategic value that even one difficult-to-locate submarine can provide.
• A submarine's central advantage is uncertainty about its location. Because an opponent cannot easily know where a hidden boat is patrolling, it must consider that surveillance or an attack could come from many places, giving even small fleets significant defensive value.
• Most smaller submarine fleets use diesel engines that require oxygen and must periodically recharge onboard batteries near the surface. Running those engines creates noise and exposure, making these boats less persistent and potentially easier to detect than nuclear-powered submarines.
• Nuclear-powered submarines can remain underwater without surfacing for air because their reactors provide sustained energy. The onboard process also produces oxygen and drinkable water, so food and other supplies for the crew become the practical constraints on exceptionally long submerged patrols.
• Israel's five modern submarines serve as a regional deterrent, and two can remain underwater for up to a week without taking in oxygen. The transcript says the US government believes Israeli submarines can carry nuclear-warhead missiles, although Israel denies that capability.
• Australia's planned nuclear-powered submarines are part of a historic arrangement with the United States and United Kingdom. The plan illustrates how the United States is strengthening alliances near China and how nuclear propulsion can shift a navy from coastal defense toward longer-range power projection.
• North Korea's fleet demonstrates why quantity alone can mislead. Experts estimate that it could have as many as 85 submarines, while the presentation uses a conservative figure of 36, but some boats are at least 50 years old and their operational condition is disputed.
• China's 58-submarine fleet includes six nuclear-missile boats and six nuclear-powered attack submarines, but most of its vessels are older diesel designs. Russia operates 62 submarines, half are nuclear-powered, and 12 can launch nuclear weapons, giving its fleet capabilities beyond raw numerical size.

Questions & Answers

Q: Which countries have the strongest submarine fleets?

The transcript identifies China and Russia as major submarine powers but shows that strength cannot be determined by fleet size alone. China has 58 submarines, while Russia has 62; half of Russia’s fleet is nuclear-powered, and 12 of its submarines can launch nuclear weapons.

Q: How many known military submarines are there worldwide?

The presentation counts 471 known military submarines across 43 countries. It notes that experts dispute the exact totals because reliable information about national fleets is limited.

Q: Why can even one submarine strengthen a small navy?

A submarine’s location is difficult for an opponent to determine, creating uncertainty about possible surveillance or attack. This can make adversaries reconsider approaching or striking a country’s coastal waters.

Q: What limits diesel-powered submarines?

Diesel engines require oxygen, so these submarines must periodically approach the surface and run their engines to recharge their batteries. The engines are loud, and the recharging cycle increases exposure compared with nuclear-powered submarines.

Q: Why are nuclear-powered submarines more capable?

Their onboard reactors provide sustained energy without requiring atmospheric oxygen, enabling longer and quieter underwater patrols. The process also produces oxygen and drinkable water, leaving food and other crew supplies as the main practical limits on endurance.

Q: Why is North Korea’s submarine count a poor measure of strength?

North Korea may have as many as 85 submarines, although the presentation uses a conservative estimate of 36. Some boats are at least 50 years old, their operational condition is disputed, and only around eight diesel submarines are described as capable of long-range patrols.

Q: How do China’s and Russia’s submarine fleets compare?

China has 58 submarines, including six nuclear-missile submarines and six nuclear-powered attack submarines, but most are older diesel designs. Russia operates 62 submarines, half are nuclear-powered, and 12 can launch nuclear weapons.

Q: How does Israel use its submarine fleet for deterrence?

Israel operates five modern submarines to deter regional enemies, including Iran. Two can remain underwater for up to a week without taking in oxygen and travel up to 4,500 kilometers; the US government believes Israeli submarines can carry nuclear-warhead missiles, although Israel denies that capability.

Summary & Key Takeaways

• The world has at least 471 known military submarines distributed among 43 countries, although experts dispute the precise figures. Most countries operate fewer than a dozen boats. Even a small fleet can strengthen coastal defense because hidden submarines force opponents to consider possible surveillance or attack across a wide area.

• Most smaller navies rely on diesel-powered submarines that must periodically approach the surface and run loud engines to recharge their batteries. Nuclear reactors remove this oxygen requirement, provide immense energy, and help produce oxygen and drinking water. Nuclear-powered boats can therefore patrol quietly across greater distances, limited mainly by human supplies.

• Fleet size does not directly measure capability. North Korea may possess numerous submarines, but some are at least 50 years old and experts question their functionality. China is expanding and modernizing a largely diesel fleet, while half of Russia's 62 submarines are nuclear-powered and 12 can launch nuclear weapons.